Modern-day slavery and human trafficking are still widespread, with victims being forced to work at nail salons, in agriculture, and in hospitality, according to the Wilberforce Institute for the study of Slavery and Emancipation.

Academics from the department at the University of Hull polled people's views on slavery in the UK and found fewer than 1 in 10 people were aware of the issue.

Researchers found the vast majority of people associated slavery with sex workers, whereas the reality is that labour abuse is the most widespread form of modern-day slavery, with exploitation running through a number of supply chains in agriculture, construction, and hospitality.

Domestic servitude, organ harvesting, and agriculture also featured highly in public awareness, it found, though half of those polled were unaware what signs could point to someone having become a victim.

John Oldfield, head of the research department, urged members of the public to look out for signs that someone may have been trafficked and to report concerns.

Victims, who are often brought to the UK on false pretences of paid work and kept in debt bondage, may seem under the control of or being influenced by someone else, he said, or may have little freedom of movement.

The Home Office estimates 13,000 people in the UK are affected by modern slavery, but because of the fragmented and underground nature of the crime, Oldfield said, reliable data is still needed to estimate the full extent.

This is also because traffickers across Europe are also able to take advantage of the free movement of people to exploit workers unaware of their rights by bringing them into the UK for work, he said.

"Modern slavery is not just about women sex workers," he said, "what it's about is people working [and being exploited] – this hidden aspect is crucial."

On Sunday the Salvation Army, which has run the government’s contract to support victims of human trafficking and modern slavery in England and Wales since 2011, said it provided support to more than 2,000 victims in 2015, almost a third more than the year before.

Nearly half of these had been referred after being trafficked for sexual exploitation, 42% had been referred for labour exploitation, and 13% for domestic servitude, the charity said. Support is defined as providing safe housing accommodation and outreach advice.

Albanian women were the most frequently referred nationals, followed by Nigerian women, the Salvation Army said. Polish and Romanian nationals were the most frequently referred men.